Path: utzoo!utgpu!cunews!micor!latour!ecicrl!clewis
From: clewis@ferret.ocunix.on.ca (Chris Lewis)
Newsgroups: comp.unix.shell
Subject: Re: the #! notation
Message-ID: <1198@ecicrl.ocunix.on.ca>
Date: 24 Jan 91 05:18:33 GMT
References: <1991Jan21.174803.6661@mp.cs.niu.edu> <16209@burdvax.PRC.Unisys.COM> <587@fciva.FRANKCAP.COM> <1991Jan23.044019.4807@NCoast.ORG>
Distribution: na
Organization: Elegant Communications Inc., Ottawa, Canada
Lines: 22

In article <1991Jan23.044019.4807@NCoast.ORG> allbery@ncoast.ORG (Brandon S. Allbery KB8JRR) writes:
|As quoted from <587@fciva.FRANKCAP.COM> by dag@fciva.FRANKCAP.COM (Daniel A. Graifer):
|+---------------
|| Perhaps I've missed something here, but none of this #! stuff works on my
|| machine (running Sys V/386 3.1).  Is this something that only works in 
|| BSD-derived unixes?  What about V3.2 or V4?
|+---------------

|It's a BSD-ism (and requires some kernel hacks to implement).

|Note that some shells can emulate this mechanism when the kernel doesn't
|support it --- I think bash does, for instance, and I have posted my "bexec"
|mechanism for making any System V csh do so many times.

Certain "stock" C-shells do it too.  I believe that BSD C shell manages
to recognize the "#" versus non-"#" prolog and attempts to do the right
thing as a short-cut.  Other C-shells too, for example, some flavours
of Xenix do it in the C-shell because there are no hooks in the kernel.
-- 
Chris Lewis, Phone: (613) 832-0541, Internet: clewis@ferret.ocunix.on.ca
UUCP: uunet!mitel!cunews!latour!ecicrl!clewis
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